The present band-like structure serves as a medical implant for the reinforcement and/or the replacement of ligaments in the pelvic region. Said ligaments in the true pelvis often become weaker or completely fail with increasing age, which in the case of female patients may lead to a lowering of the uterus or the vagina. From a certain severity onwards, reference is made even to a corresponding prolapse. This displacement of the uterus or the vagina often also leads to a displacement of the position of the urinary bladder in the sub-peritoneal space, or to a variation of the forces which act on the urinary bladder in comparison to the healthy state. Incontinence is then often the consequence.
From the prior art it is known to treat such displacements or prolapses with an artificial suspension of the affected organs, which were previously retained by the endogenous ligaments, on anatomically suitable fastening locations.
U.S. Pat. No. 6,575,897, which is considered the closest prior art, thus discloses a suspension device having a two-dimensional central textile and two also two-dimensional lateral textiles made from the same textile material, which are interconnected by a string-like band, which is also made from the identical textile material. The band is sewn or welded onto the central textile—which may also be referred to as central section—and onto both lateral textiles—correspondingly referred to as lateral sections. During a surgical procedure, the central textile is now fastened to the organ to be supported. This location may also be referred to as traction point. As a rule, this is usually either the uterus or, in the frequent case in which a hysterectomy has already been performed, the remaining cervix or the vaginal stump. The two lateral textiles are then guided out of the sub-peritoneal space through openings in the peritoneum in order to be subsequently fastened to a suitable fastening location, which often is osseous, such as, for example, the sacral bone. In this manner, the affected organ is returned to its original position and any possible displacement ruled out again.
However, this suspension device for the augmentation of ligaments has several significant disadvantages. In order for a contact which is to be load-bearing in the long term to develop on the traction point corresponding to the location to be supported, for example the cervix, and on the fastening locations, in this case the sacral bone, meshes in the textile which are as large as possible are of advantage, since they favor the ingrowth of tissue into the meshes of the textile. However, the effective porosity of the structure is very considerably reduced by the superimposition of the two textiles, especially in the sections where, according to the prior art, the band is attached to the central textile or the lateral textiles. It is obvious that no identical overlaying of the meshes of the band with the meshes of the central textile or those of the lateral textiles can be achieved in practice, which is why the porosity created at these locations is for this reason alone, in principle, only half of that compared to the state in which there is no superimposition.
It is to be noted in this context that it is not relevant to the porosity, being fundamentally defined as the percentage of open surface in relation to the total surface of the textile, what porosity the respective textile has in its original state, but rather what the effective porosity is after the application of said textile. The porosity in the original state is, for example, diminished in that inevitably granuloma and scar tissue envelop the individual strands of the textile because of the response of the body to foreign material, as a result of which open surface is naturally lost. In the extreme case, a complete closure of the net meshes which form the pores may occur as a result of this reaction. The term effective porosity, which is relevant in this case, is known to the person skilled in the art from the essay “New Objective Measurement to Characterize the Porosity of Textile Implants” by Muhl, Binnebosel, Klinge and Goedderz (Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2007.84B(1): p. 176/183), to which specific reference is made here.
The superimposition of the two textile net structures of the central textile and/or the lateral textile and the band thus leads to a disproportionately high reduction of the effective porosity in the mentioned sense, as a result of which the ingrowth of the implant into the tissue is made considerably difficult especially at the traction point.
This problem is additionally aggravated in that the superimposition of the textiles not only affects the porosity, but in these sections also the bending property of the material as a whole. As a result, an exact adaption to the tissue is no longer so easily possible, something that would, however, also be of advantage to the already mentioned ingrowth of the tissue into the implant.
For these two reasons, a poorer hold is provided exactly at the particularly important locations at which the intrinsic contact with the fraction point and the fastening locations is made than in the peripheral regions of the central textile or the lateral textiles.
In addition to this, the fastening of the band on the central textile and on both lateral textiles must hold unconditionally throughout the entire service life of the suspension device. In the case of a detachment of the welded or sutured connection, for whatever reason, from even just one of these locations, the organ can no longer be supported and the fundamentally same situation occurs as prior to the use of the suspension device, including the corresponding necessity for another surgical procedure to be carried out on the patient.
Furthermore, the known textile material has no provision against any constriction. The suspension device is exposed not only to a constant tensile load, but also to a dynamic tensile load which results from, for example, a variation in the filling level of the urinary bladder and the body movements of the patient. This tensile load on the suspension device may, however, lead to a constrictive deformation of the individual meshes of the textile material. As a result of such a constriction, not only are the meshes diminished in their area size, which leads to a corresponding reduction of the effective porosity, but any intergrowth already established between tissue and the individual meshes is also severed again and torn open. This, too, slows the process of ingrowth and reduces the quality of the fastening of the suspension device.
Consequently, the object underlying the invention is that of refining and further developing the band-like structure for the augmentation of a ligament according to the prior art, and its corresponding method of manufacture, in such a manner that an improved connection is achieved between said band-like structure and the tissue at the contact locations.